1. Field of the Invention
The present invention relates to water wells, and more particularly to a system for automatically chemically treating well water in the well.
2. Brief Description of the Prior Art
It is desirable in water wells to treat the water with oxidizing or chelating chemicals for purification purposes. In some installations, a retention chamber is placed in the water line from the pump with dry chemicals being fed into the chamber. It is also known to provide an opening into the well casing 13 into which chemical pellets are introduced to be dissolved. In such instances, water in the well casing when the pump is not operating will achieve a specific static level dependent upon the pressure from the aquifer which equalizes with the atmospheric pressure. The pellets will slowly dissolve in the water at this level. In instances where the pump is well below the static water level or, for an external pump the standpipe is well below the static water level, it is difficult to obtain a uniform concentration of the chemical with the result that either too much or too little may be present at any given time. Part of the problem is that the water is drawn at a deeper point in the well than the static water level and there is little if any tendency for the dissolved chemical to sink to the point at which water is being withdrawn.
Thus, there is a need for a system which will automatically treat the water in the well to the preferred concentration of the oxidizing or chelating agent and which will maintain such concentration over long periods of time.
While systems are known for adding chlorine and the like to swimming pools and the like, none of these appear suitable for wells. In U.S. Pat. No. 4,188,295 to Burnett, a chamber is provided into which a stick of chlorine is placed and depends upon water continuously circulating through the swimming pool and passing through the chamber to erode chlorine from the stick. A venturi to introduce chlorine into waste water is shown in U.S. Pat. No. 4,333,833 to Longley et al. U.S. Pat. No. 4,584,106 to Held teaches a mixing chamber having chlorine tablets wherein water is passed through the mixing chamber with means provided for controlling the size of the particles of chlorine tablets that will flow out of the chamber into the system. Jenkins, U.S. Pat. No. 3,899,027, teaches apparatus for cleaning the casing and other elements of a well by shutting off the output and recirculating all of the pumped water into the casing with a non-potable cleaning solution dissolved therein. The well must be purged after cleaning.